LisaList2

The Lisa 2/10 I/O board includes a socket for a WD2001 encryption device.

No known Lisa software uses the WD2001 and the 1/5 I/O Board does not have a socket for an encryption device.

(My guess it was added as a means to satisfy requirements of, or limit competition to the Lisa in, US government contract bids)

According to the data sheet, the cipher was DES and these devices were export-controlled.